Stretchable sheet and method for producing the same

ABSTRACT

A sheet is produced by
         (i) producing a sheet by entangling woven or knitted material including a thread composed of a composite fiber such that two kinds or more of polyethylene terephthalate polymers different in intrinsic viscosity are stuck together in a side-by-side type along the fiber length direction and/or of a core-in-sheath type composite fiber such that two kinds or more of polyethylene terephthalate polymers different in intrinsic viscosity form an eccentric core-in-sheath structure, with a fiber capable of converting into ultra fine fibers composed of two kinds or more of polymeric substances different in solubility in solvent,   (ii) developing an ultra fine fiber with an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less by treating the sheet with a solvent to thereafter provide elastomer having polyurethane as a main component by impregnating and solidifying solvent solution of elastomer having polyurethane as a main component into the sheet, or of providing elastomer having polyurethane as a main component by impregnating and solidifying solvent solution of elastomer having polyurethane as a main component into the sheet to thereafter develop an ultra fine fiber with an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less by treating the sheet with a solvent, and   (iii) rubbing and shrinking the woven or knitted material under the condition of 110° C. or more.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Divisional Application of application Ser. No. 12/531,817,filed Sep. 17, 2009, which is the U.S. National Phase Application ofPCT/JP2008/054574, filed Mar. 13, 2008, which claims priority toJapanese Application No. 2007-070327 filed on Mar. 19, 2007.

FIELD OF THE INVENTION

The present invention relates to a sheet excellent in surfaceappearances, touch, stretch ratio and stretch-back ratio, and to amethod for producing thereof.

BACKGROUND OF THE INVENTION

A sheet mainly composed of ultra fine fiber and elastomer has anexcellent characteristic not exhibited by natural leather, and has beenused for clothing, chair upholstery and automobile interior materialsmore widely year by year. Recently, a sheet excellent in stretchabilityhas been demanded particularly from the viewpoint of comfortability towear in clothing use and moldability in material use. Various studieshave been made for such demand.

For example, a method for inserting woven or knitted material usingpolytrimethylene terephthalate fiber into textile for artificial leatheras described above is described in Patent Document 1. Although thismethod utilizes stretchability due to the crystal structure ofpolytrimethylene terephthalate, the stretchability is low because ofhigh-density nonwoven fabric with single fibers entangled with eachother and allowed polyurethane to constrain the woven or knittedmaterial from moving firmly. In addition, the fiber length of an ultrafine fiber for forming the nonwoven fabric is as short as 20 mm or lessthat repetitive stretching untangles the entanglement to bringdeterioration in grade.

Also, a method for inserting woven or knitted material using potentialcrimping fiber composed of high shrinkage polyester and low shrinkagepolyester is described in Patent Document 2. This method impartsstretchability, in which the woven or knitted material composed ofpotential crimping fiber is heat-treated to develop crimp, and the crimpis integrated with a fiber capable of converting into ultra fine fibersby needle punching. In the woven or knitted material made of the fiberhaving developed crimp, the crimped fiber is so easily hooked on aneedle as to be cut when integrated with a fiber capable of convertinginto ultra fine fibers. Thus, the woven or knitted material with the cutfiber develops stretchability with difficulty. Polyurethane is providedafter developing crimp in the woven or knitted material, and so the formof the sheet itself is fixed and stretchability thereof is developedwith difficulty.

In addition, a method for inserting woven or knitted material usingpolyurethane fiber into nonwoven fabric for artificial leather isdescribed in Patent Document 3. However, it is known that polyurethaneis deteriorated with time, and the fabric by the method vanishes instretchability due to use for many years. As in Patent Document 1, thefiber length of an ultra fine fiber is so short that repetitivestretching untangles the entanglement in the ultra fine fibersthemselves to bring deterioration in grade.

That is to say, a method for obtaining a sheet excellent in surfaceappearances, touch, stretch ratio and stretch-back ratio has not beenobtained so far.

Patent Document 1: Japanese Unexamined Patent Publication No. 11-269751

Patent Document 2: Japanese Unexamined Patent Publication No.2000-336581

Patent Document 3: Japanese Unexamined Patent Publication No. 2004-91999

SUMMARY OF THE INVENTION

The present invention provides a sheet excellent in surface appearances,touch, stretch ratio and stretch-back ratio, and a method for producingthereof in view of the background of the prior art.

Embodiments of the present invention include any one of the following:

(1) a method for producing a stretch sheet, including the followingsteps (i) to (iii) in this order;

(i) a step of producing a sheet by entangling woven or knitted materialincluding a thread composed of a composite fiber such that two kinds ormore of polyethylene terephthalate polymers different in intrinsicviscosity are stuck together in a side-by-side type along the fiberlength direction and/or of a core-in-sheath type composite fiber suchthat two kinds or more of polyethylene terephthalate polymers differentin intrinsic viscosity form an eccentric core-in-sheath structure, witha fiber capable of converting into ultra fine fibers composed of twokinds or more of polymeric substances different in solubility insolvent,

(ii) a step of developing an ultra fine fiber with an average singlefiber fineness of 0.001 dtex or more and 0.5 dtex or less by treatingthe sheet with a solvent to thereafter provide elastomer havingpolyurethane as a main component by impregnating and solidifying solventsolution of elastomer having polyurethane as a main component into thesheet, or of providing elastomer having polyurethane as a main componentby impregnating and solidifying solvent solution of elastomer havingpolyurethane as a main component into the sheet to thereafter develop anultra fine fiber with an average single fiber fineness of 0.001 dtex ormore and 0.5 dtex or less by treating the sheet with a solvent, and

(iii) a step of rubbing and shrinking the woven or knitted materialunder the condition of 110° C. or more;

(2) the method for producing a stretch sheet according to (1), in whichelastomer having polyurethane as a main component is provided afterdeveloping an ultra fine fiber in step (ii);

(3) the method for producing a stretch sheet according to (2), in whichthe step of providing water-soluble resin to the sheet is performedbefore step (ii);

(4) a stretch sheet including woven or knitted material including threadcomposed of a composite fiber such that two kinds or more ofpolyethylene terephthalate polymers different in intrinsic viscosity arestuck together in a side-by-side type along the fiber length directionand/or of a core-in-sheath type composite fiber such that two kinds ormore of polyethylene terephthalate polymers different in intrinsicviscosity form an eccentric core-in-sheath structure, an ultra finefiber with an average single fiber fineness of 0.001 dtex or more and0.5 dtex or less, and elastomer having polyurethane as a main component,in which the thread composing woven or knitted material has a structurehaving a cavity in its inside;

(5) the stretch sheet according to (4), in which the elastomer ispartially joined to the thread having a cavity;

(6) the stretch sheet according to (4) or (5), in which stretch ratio inlongitudinal direction and/or transversal direction is 15% or more and35% or less, and stretch-back ratio in longitudinal direction and/ortransversal direction is 80% or more and 100% or less;

(7) the stretch sheet according to any one of (4) to (6), in which thecontent of the polyurethane is 10% by weight or more and 40% by weightor less with respect to the total weight of the ultra fine fiber and thewoven or knitted material;

(8) the stretch sheet according to any one of (4) to (7), in which thepolyurethane is polycarbonate polyurethane having a polycarbonateskeleton represented by the following general formulae (1) and (2); and

(in the formula, R₁ and R₂ are aliphatic hydrocarbon groups with acarbon number of 7 to 11, and may be same or different. n and m arepositive integers, and R₁ and R₂ are block copolymerization or randomcopolymerization in the case of being different.)

(in the formula, R₃ and R₄ are aliphatic hydrocarbon groups with acarbon number of 3 to 6, and may be same or different. x and y arepositive integers, and R₃ and R₄ are block copolymerization or randomcopolymerization in the case of being different.)

(9) the stretch sheet according to any one of (4) to (8), in which thefiber length of the ultra fine fiber is 25 mm or more and 90 mm or less.

According to an embodiment of the present invention, woven or knittedmaterial including a thread composed of a composite fiber such that twokinds or more of polyethylene terephthalate polymers different inintrinsic viscosity are stuck together in a side-by-side type along thefiber length direction and/or of a core-in-sheath type composite fibersuch that two kinds or more of polyethylene terephthalate polymersdifferent in intrinsic viscosity form an eccentric core-in-sheathstructure are entangled with a fiber capable of converting into ultrafine fibers and make that into a state of a sheet, and thereafter rubbedand shrunk under the condition of 110° C. or more to develop crimp inthe thread, so that the thread composing woven or knitted material has acavity in the inside, and a sheet excellent in surface appearances,touch, stretch ratio and stretch-back ratio can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a method for confirming the presence or absenceof a cavity in the inside of a thread.

REFERENCE NUMERALS

-   -   A: a line connecting the outer periphery of a thread and the        center of an approximate circle thereof    -   B: a portion with the line A and the fiber superposed

DETAILED DESCRIPTION OF THE INVENTION

The stretch sheet in an embodiment of the present invention is a sheetincluding woven or knitted material including a thread composed of acomposite fiber such that two kinds or more of polyethyleneterephthalate polymers different in intrinsic viscosity are stucktogether in a side-by-side type along the fiber length direction and/orof a core-in-sheath type composite fiber such that two kinds or more ofpolyethylene terephthalate polymers different in intrinsic viscosityform an eccentric core-in-sheath structure, an ultra fine fiber with anaverage single fiber fineness of 0.001 dtex or more and 0.5 dtex orless, and elastomer having polyurethane as a main component, andcharacterized in that the thread composing woven or knitted material hasa structure having a cavity in its inside.

The woven or knitted material in an embodiment of the present inventionis a woven or knitted material including a thread composed of acomposite fiber such that two kinds or more of polyethyleneterephthalate polymers different in intrinsic viscosity are stucktogether in a side-by-side type along the fiber length direction and/orof a core-in-sheath type composite fiber such that two kinds or more ofpolyethylene terephthalate polymers different in intrinsic viscosityform an eccentric core-in-sheath structure, and the thread composing thewoven or knitted material has a cavity in its inside. In the threadobtained by spinning and drawing so as to form a structure such thatpolyethylene terephthalate polymers different in intrinsic viscosity arestuck together in a side-by-side type along the fiber length directionand/or an eccentric core-in-sheath structure, internal strains differentbetween two components is caused by stress concentration on the higherviscosity side during drawing. Due to such internal strains, the higherviscosity side is shrunk so greatly by elastic recovery difference afterdrawing and heat shrinkage difference in the after-mentioned shrinkingstep of woven or knitted material (the step (iii)) that strain is causedin single fiber to develop crimp. As described later, woven or knittedmaterial is entangled with a fiber capable of converting into ultra finefibers and made into a sheet, and thereafter rubbed and shrunk under thecondition of 110° C. or more, so that the thread composing woven orknitted material has a structure having a cavity in its inside(hereinafter referred to as a hollow structure). This hollow structureof the thread exhibits stretchability in the sheet, and provides bulgesto the sheet and voids inside the sheet, so that soft touch and moderateresiliency are felt and a satisfactory sense of hand feeling isobtained. Strong shrinkage force of woven or knitted material increasesfiber density on the surface of the sheet, and minute grade of highquality and favorable touch are obtained.

The composite fiber stuck together in a side-by-side type and thecore-in-sheath type composite fiber are composed of two kinds ofpolyethylene terephthalate polymers, and the intrinsic viscositydifference of the two kinds of polyethylene terephthalate polymers ispreferably 0.2 or more.

The intrinsic viscosity difference of polyethylene terephthalatecopolymers may be set at desired viscosity by properly adjusting time,temperature, catalytic amount and copolymerization component inpolymerization.

The intrinsic viscosity in the present invention is a value measured ata temperature of 25° C. by dissolving a sample in ortho-chlorophenol asdescribed later.

The polyethylene terephthalate polymers in embodiments of the presentinvention have as a main component a structure such that terephthalicacid or derivatives thereof are copolymerized with ethylene glycol orderivatives thereof, and the main component herein signifies more than50% by weight with respect to the total weight. Copolymerizationcomponents capable of forming other ester linkages may be contained.Examples of copolymerizable compounds include dicarboxylic acids such asisophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipicacid, dimer acid, sebacic acid and 5-sodium isophthalate, and diols suchas ethylene glycol, diethylene glycol, butanediol, neopentyl glycol,cyclohexanedimethanol, polyethylene glycol and polypropylene glycol, butnot limited thereto. Titanium dioxide as a flatting agent, particulatesof silica and alumina as a lubricant, and hindered phenol derivativesand coloring pigment as an antioxidant may be added as required.

In an embodiment of the present invention, it is preferred thatcomposite fiber composing woven or knitted material is composed ofpolyethylene terephthalate polymers; the reason thereof is to have themost appropriate properties in the production of the stretch sheet ofthe present invention in an exemplary embodiment. For example, in thecase where a sheet is produced by using woven or knitted materialcomposed of composite fiber using polytrimethylene terephthalate,polytrimethylene terephthalate has properties sensitive against heat asto be easily shrunk by heat. Thus, in the case of processing a sheet byapplying these woven or knitted material, crimp is developed by heatapplied during processing in the unintended step, and consequently asheet poor in stretchability is easily made. On the other hand,composite fiber using polyethylene terephthalate develops crimp atrelatively high temperature, so that crimp may be prevented from beingdeveloped in the unintended step and a sheet excellent in stretchabilitycan be obtained. The composite fiber composed of polyethyleneterephthalate polymers has a sense of resiliency, so that a moderatesense of resiliency is offered in the case of being made into a sheet toprovide a favorable sense of hand feeling.

With regard to each intrinsic viscosity of polyethylene terephthalatepolymers, the intrinsic viscosity difference between high viscositycomponent and low viscosity component is preferably 0.2 or more.

The compound ratio of both components is preferably a range of highviscosity component: low viscosity component=75:25 to 35:65 (% byweight), more preferably a range of 65:35 to 45:55 (% by weight) in viewof filature and the formation of a cavity in a thread composed ofcomposite fiber.

The fiber cross-sectional shape of composite fiber may be a circularcross section, a triangular cross section, a multilobar cross section, aflat cross section, an X-shaped cross section and other various kinds ofirregular cross sections, and is not particularly limited. It ispreferable that a semicircular side-by-side type of a circular crosssection be used from the viewpoint of a balance between crimpdevelopment and touch, a hollow side-by-side type be used from theviewpoint of a balance between light weight, thermal insulation and asense of resiliency, and a side-by-side type of a triangular crosssection be used from the viewpoint of dry touch.

The composite fiber preferably has a twisting factor of 5000 or more and25000 or less. A twisting factor of 5000 or more prevents thread frombeing damaged in being entangled with a fiber capable of converting intoultra fine fibers and made into a sheet in the later processing, while atwisting factor of 25000 or less provides sufficient stretchability;more preferably, 8000 or more and 20000 or less. The twisting factor Kherein is:twisting factor K=T×D ^(0.5)

wherein T: number of twist per 1 m of thread length (times), D: finenessof a thread (dtex)

The number of twist per 1 m of thread length T is a value such that thenumber of untwisting in completely untwisting by an electric twisttester under a load of 90×10⁻³ cN/dtex is divided by thread length afteruntwisting.

The woven or knitted material in an embodiment of the present inventionis preferably composed of the composite fiber of a side-by-side type anda core-in-sheath structure as described above entirely, and may includeother fibers without deteriorating the effect of the present invention.For example, the use of the composite fiber as described above for onlyweft yarn or only warp yarn provides stretchability in only transversaldirection or only longitudinal direction.

In the present invention, the woven or knitted material is a genericterm for woven fabrics and knitted fabrics, and structure thereof is notparticularly limited. Examples of woven fabrics include plain weaves,twill weaves and satin weaves; preferably, plain weaves in view ofcosts. Examples of knitted fabrics include round braid, tricot andraschel.

Examples of ultra fine fibers composing the stretch sheet of the presentinvention include polyesters such as polyethylene terephthalate,polybutylene terephthalate, polytrimethylene terephthalate andpolyethylene 2,6-naphthalene dicarboxylate, polyamides such as 6-nylonand 6,6-nylon, and various kinds of synthetic fibers such as acrylicpolyethylene and polypropylene. Among them, polyester fibers such aspolyethylene terephthalate, polybutylene terephthalate andpolytrimethylene terephthalate are preferably used from the viewpoint ofstrength, dimensional stability, light resistance and dye-affinity. Thesheet may be composed of plural kinds of ultra fine fibers made ofdifferent raw materials by mixture.

In order to improve hiding, inorganic particles such as titanium oxideparticles, a lubricant, a pigment, a heat stabilizer, an ultravioletabsorbing agent, a conductive agent, a heat storage agent and ananti-fungus agent may be also added to these polymers in accordance withvarious kinds of purposes.

It is beneficial that the average single fiber fineness of ultra finefibers composing the stretch sheet is selected to be 0.001 dtex or moreand 0.5 dtex or less from the viewpoint of flexibility and nap grade ofthe sheet; preferably 0.3 dtex or less, more preferably 0.2 dtex orless. On the other hand, the average single fiber fineness is preferably0.005 dtex or more, more preferably 0.01 dtex or more from the viewpointof chromogenic properties after dyeing, and dispersibility and easinessto separate the fibers during treatment of raising such as buffing bysandpaper or the like.

The average single fiber fineness of ultra fine fibers is calculated insuch a manner that a scanning electron microscope (SEM) picture of thesheet surface is taken to randomly select circular or elliptic close tocircle fibers by 100 pieces and measure the fiber diameters, which areconverted into fineness by specific gravity of the raw material polymerto further calculate average value thereof.

The cross-sectional shape of ultra fine fibers may be a circular crosssection, and may adopt an ellipse, a flat shape a polygonal crosssections such as a triangle, and irregular cross sections such as a fanshape and a cross shape. The average single fiber fineness of a fiberhaving an irregular cross section is calculated in such a manner thatfineness of the fiber cross section with respect to the circumcircle iscalculated and is multiplied by the area ratio of the fiber crosssection to the circumcircle.

The ultra fine fibers as described above are preferably laminated andentangled in the form of nonwoven fabric with the woven or knittedmaterial. The nonwoven fabric (hereinafter referred to as ultra finefiber web) may be staple fiber nonwoven fabric or filament fibernonwoven fabric; preferably, staple fiber nonwoven fabric in the case ofemphasizing much of touch and grade. In the case of staple fibernonwoven fabric, the fiber length is preferably 25 mm or more and 90 mmor less. A fiber length of 90 mm or less allows favorable grade andtouch, while a fiber length of 25 mm or more allows a sheet to haveabrasion resistance and to tolerate repetitive stretching. For example,in the case of using very short staple fiber in a papermaking method,the fiber falls off greatly and the nap on the surface vanishes, and thestaple fiber is untangled by repetitive stretching to remarkablydeteriorate the grade of the sheet. In order to restrain this, anincrease in the added amount of elastomer having polyurethane as a maincomponent leads to the hardening of touch and the deterioration ofstretchability. However, in the case of the fiber length in theabove-mentioned range, a structure where the ultra fine fibers arefirmly entangled does not cause the falling off of many fibers and theuntanglement of the fibers by repetitive stretching, and enablesfavorable grade to be maintained.

In an embodiment of the present invention, elastomer having polyurethaneas a main component is provided to a sheet composed of woven or knittedmaterial made of the composite fiber and ultra fine fibers. Theelastomer is a polymer having rubber elasticity for expansion andcontraction, and examples thereof include polyurethane, SBR, NBR andacrylic resin. The main component herein signifies that the weight ofpolyurethane is more than 50% by weight with respect to the weight ofthe whole elastomer.

Polyurethane having a structure such that polyol, polyisocyanate andchain extender are properly reacted can be used as polyurethane used foran embodiment of the present invention.

Polycarbonate diol, polyester diol, polyether diol, silicone diol,fluorine diol and copolymer therewith may be used as polyol. Among them,polycarbonate diol and polyester diol are preferably used from theviewpoint of light resistance. In addition, shrinkage under thecondition of high temperature is performed for allowing a structurehaving a cavity at the center to the composite fiber composing woven orknitted material in a sheet, and polycarbonate is more preferable inview of having heat resistance to this high temperature condition.

Polycarbonate diol can be produced by transesterification of alkyleneglycol and carbonate, or reaction of phosgene or chloroformate andalkylene glycol. Examples of alkylene glycol include straight-chainalkylene glycols such as ethylene glycol, propylene glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol and1,10-decanediol, branched alkylene glycols such as neopentyl glycol,3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol and2-methyl-1,8-octanediol, alicyclic dial such as 1,4-cyclohexanediol,aromatic dial such as bisphenol A, glycerin, trimethylolpropane, andpentaerythritol. Both polycarbonate dial obtained from each alkyleneglycol singly and copolymerized polycarbonate diol obtained from twokinds or more of alkylene glycols may be used.

Examples of polyisocyanate include aliphatics such as hexamethylenediisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanateand xylylene diisocyanate, and aromatics such as diphenylmethanediisocyanate and tolylene diisocyanate; these may be used incombination. Among them, aliphatics such as hexamethylene diisocyanate,dicyclohexylmethane diisocyanate and isophorone diisocyanate arepreferable from the viewpoint of light resistance.

Examples of chain extender include amines such as ethylenediamine andmethylenebisaniline, diol such as ethylene glycol, and polyamineobtained by reacting polyisocyanate with water.

With regard to polyurethane used for an embodiment of the presentinvention, the softening point is preferably 200° C. or more and 300° C.or less. A softening point of 200° C. or more allows the shape of asheet to be retained even under the high temperature condition in theshrinking step (the step (iii)) performed for forming a cavity inside athread composing woven or knitted material, where the thread is composedof the composite fiber. A softening point of 300° C. or less makespolyurethane flexible and provides favorable touch as a stretch sheet.The softening point is measured in a dry film of polyurethane by using athermomechanical analysis apparatus. The softening point of polyurethaneexisting in the sheet may be measured in such a manner that polyurethaneis extracted from the sheet by using N,N′-dimethylformamide (hereinafterabbreviated as DMF) to produce a dry film with a thickness of 0.2 mm to0.4 mm.

With regard to polyurethane, the gelation point is preferably 2.5 ml ormore and 6 ml or less, more preferably 3 ml or more and 5 ml or less.The gelation point herein signifies a value of the water dropping amountwhen 100 g of DMF solution of 1% by weight-polyurethane is stirred whiledropping distilled water into this solution and becomes slightly cloudedafter the coagulation of polyurethane starts on the temperatureconditions of 25±1° C. Thus, DMF used for the measurement needs to beused at a moisture of 0.03% or less. The gelation point of polyurethaneexisting in the sheet can be measured in such a manner that polyurethaneis extracted from the sheet by using DMF to adjust the polyurethaneconcentration at 1% by weight.

This gelation point signifies moisture tolerance in wet-coagulatingpolyurethane by using polyurethane DMF solution; generally; lowergelation point tends to bring faster coagulation rate and highergelation point tends to bring slower coagulation rate. Thus, in the casewhere the gelation point is less than 2.5 ml, the coagulation rate is sofast in wet-coagulating polyurethane resin that the foaming ofpolyurethane existing inside a nonwoven fabric easily becomes large andcoarse. As a result of easily causing partial foaming failure, inferiornap grade with uneven nap length of the surface is easily brought in thecase of buffing the surface of a sheet by sandpaper. The polyurethanefilm is so thin that the effect as a binder for fixing the fibersbecomes too small, and the problem is that many fibers fall off in thecase of fretting the surface grade by a brush or the like. On the otherhand, in the case where the gelation point is more than 6 ml, thecoagulation rate is so slow in wet-coagulating polyurethane resin thatthe foaming is scarcely observed in polyurethane existing inside anonwoven fabric and polyurethane tends to exist as thick and hard film.Thus, in the case of buffing the surface of a sheet by sandpaper,polyurethane is buffed with difficulty and inferior grade with short napof the surface is easily brought. In addition, a thread composed of thecomposite fiber in woven or knitted material has a hollow structure withdifficulty and the sheet tends to be hard in touch and poor instretchability. The reason thereof is that polyurethane tends to existas thick and hard film, so that the sheet itself becomes hard, and thethread composed of the composite fiber in woven or knitted material ishindered from shrinking for firmly constraining woven or knittedmaterial including the thread composed of the composite fiber and ultrafine fiber.

Polycarbonate polyurethane having a polycarbonate skeleton representedby the following general formulae (1) and (2) is preferable aspolyurethane which is composed of polycarbonate polyol resistant tohigh-temperature shrinkage and which satisfies the above-mentionedsoftening point and gelation point.

(in the formula, R₁ and R₂ are aliphatic hydrocarbon groups with acarbon number of 7 to 11, and may be same or different. n and m arepositive integers, and R₁ and R₂ are block copolymerization or randomcopolymerization in the case of being different.)

(in the formula, R₃ and R₄ are aliphatic hydrocarbon groups with acarbon number of 3 to 6, and may be same or different. x and y arepositive integers, and R₃ and R₄ are block copolymerization or randomcopolymerization in the case of being different.)

In an embodiment of the present invention, elastomer having polyurethaneas a main component may contain elastomer resin such as polyester,polyamide and polyolefin-type, acrylic resin, and ethylene-vinyl acetateresin without deteriorating performance and touch as a binder, and maycontain various kinds of addition agents, for example, pigment such ascarbon black, flame retardant such as phosphorus, halogen andinorganic-type, antioxidant such as phenol, sulfur and phosphorus-type,ultraviolet absorbing agent such as benzotriazole, benzophenone,salicylate, cyanoacrylate and oxalic acid anilide-type, light stabilizersuch as hindered amine and benzoate-type, hydrolysis resistancestabilizer such as polycarbodiimide, plasticizer, antistatic agent,surface-active agent, coagulation regulator, and dyestuff.

In a stretch sheet of an embodiment of the present invention, thecontent of elastomer having polyurethane as a main component withrespect to ultra fine fiber and woven or knitted material is preferably10% by weight or more and 40% by weight or less. The content of 10% byweight or more provides abrasion resistance and shape retentionresistant to repetitive stretching. The content of 40% by weight or lessprevents the touch of the sheet from hardening, and dose not hinderwoven or knitted material from shrinking in the shrinkage of woven orknitted material in the after-mentioned shrinking step of woven orknitted material (the step (iii)), whereby stretchability can bedeveloped. The content is more preferably 15% by weight or more and 35%by weight or less, far more preferably 15% by weight or more and 30% byweight or less.

The stretch sheet may contain functional agents such as dyestuff,pigment, flexibilizer, touch regulator, pilling inhibitor, anti-fungusagent, deodorant, water repellent, light-resistant agent andweather-resistant agent.

With regard to the stretch sheet of an embodiment of the presentinvention, it is preferable that stretch ratio in longitudinal directionand/or transversal direction of the sheet is to be 15% or more and 35%or less, and stretch-back ratio in longitudinal direction and/ortransversal direction is to be 80% or more and 100% or less. A stretchratio of 15% or more provides favorable comfortability to wear,beautiful silhouette in clothing use, and favorable moldability inmaterial use. A stretch ratio of 35% or less ensures favorable grade andfavorable moldability in stretching. In addition, a stretch-back ratioof 80% or more and 100% or less provides favorable stretch-backproperties and shape retention.

Next, an embodiment of a method for producing a stretch sheet asdescribed above is described.

A method for producing a stretch sheet in an embodiment of the presentinvention includes the following steps (i) to (iii) in this order:

(i) the step of producing a sheet by entangling woven or knittedmaterial including a thread composed of a composite fiber such that twokinds or more of polyethylene terephthalate polymers different inintrinsic viscosity are stuck together in a side-by-side type along thefiber length direction and/or of a core-in-sheath type composite fibersuch that two kinds or more of polyethylene terephthalate polymersdifferent in intrinsic viscosity form an eccentric core-in-sheathstructure, with a fiber capable of converting into ultra fine fiberscomposed of two kinds or more of polymeric substances different insolubility in solvent;

(ii) the step of developing an ultra fine fiber with an average singlefiber fineness of 0.001 dtex or more and 0.5 dtex or less by treatingthe sheet with a solvent to thereafter provide elastomer havingpolyurethane as a main component by impregnating and solidifying solventsolution of elastomer having polyurethane as a main component into thesheet, or of providing elastomer having polyurethane as a main componentby impregnating and solidifying solvent solution of elastomer havingpolyurethane as a main component into the sheet to thereafter develop anultra fine fiber with an average single fiber fineness of 0.001 dtex ormore and 0.5 dtex or less by treating the sheet with a solvent; and

(iii) the step of rubbing and shrinking the woven or knitted materialunder the condition of 110° C. or more.

Performing steps (i) to (iii) in this order makes it possible to obtaina sheet excellent in surface appearances, touch, stretch ratio andstretch-back ratio.

First, step (i) is described.

In step (i), as described above, a sheet is produced by entangling wovenor knitted material including a thread composed of a composite fibersuch that two kinds or more of polyethylene terephthalate polymersdifferent in intrinsic viscosity are stuck together in a side-by-sidetype along the fiber length direction and/or of a core-in-sheath typecomposite fiber such that two kinds or more of polyethyleneterephthalate polymers different in intrinsic viscosity form aneccentric core-in-sheath structure, with a fiber capable of convertinginto ultra fine fibers composed of two kinds or more of polymericsubstances different in solubility in solvent.

A method for producing composite fiber is not particularly limited; forexample, in the case of the side-by-side type composite fiber, it can beobtained in such a manner that a high-viscosity polyethyleneterephthalate polymer is disposed as one of the two kinds ofpolyethylene terephthalate polymers and a low-viscosity polyethyleneterephthalate polymer is disposed as the other of the two kinds ofpolyethylene terephthalate polymers, joined at the exhaust port top of aspinneret, and formed into a side-by-side composite stream, and theresultant is thereafter discharged from an exhaust port for obtaining adesired cross-sectional shape. The discharged line of thread is may beproduced by a two-step method where the line is once wound up afterbeing cooled and solidified, and then is subjected to drawing and drawfalse twisting, or by a direct spin drawing method for taking up yarnand thereafter drawing directly.

Subsequently, woven or knitted material made of such composite fiber areentangled with a fiber capable of converting into ultra fine fiberscomposed of two kinds or more of polymeric substances different insolubility in solvent, and thereafter treated with a solvent in step(ii) to perform ultra-fining of the fiber, whereby a sheet with ultrafine fibers and woven or knitted material entangled is obtained.

As the fiber capable of converting into ultra fine fibers, the followingmay be adopted: a sea-island type composite fiber such that twocomponents of thermoplastic resins different in solubility in solventare regarded as a sea component and an island component to make theisland component into ultra fine fibers by removing the sea component bydissolving it with the use of solvent; and a peeling type compositefiber such that the two components of thermoplastic resins arealternately disposed with the fiber surface radially or multilayered,and divided into ultra fine fibers by peeling and dividing by solventtreatment. Among them, the sea-island type composite fiber is preferablealso from the viewpoint of flexibility and touch of a base material forthe reason that the removal of the sea component provides a moderatevoid between the island components, that is, between the ultra finefibers inside a fiber bundle.

Examples of the sea-island type composite fiber include a fiber by analternate polymer arrangement method such that two components of sea andisland are alternately arranged and spun by using a sea-island typecomposite spinneret, and a fiber by a mix spinning method such that twocomponents of sea and island are mixed and spun; the sea-island typecomposite fiber by an alternate polymer arrangement method is morepreferable in view of providing ultra fine fibers with uniform fineness.

In the case of the sea-island type composite fiber, as the seacomponent, polyethylene, polypropylene, polystyrene, copolymerizationpolyester such that sodium 5-sulfoisophthalate and polyethylene glycolare copolymerized, polylactic acid, and water-soluble thermoplasticpolyvinyl alcohol resin can be used.

The fiber capable of converting into ultra fine fibers is preferablysubjected to crimp processing, cut into a predetermined length, madeinto a nonwoven fabric (an ultra fine fiber web) by a cloth wrapper, andlaminated and entangled in the form of the nonwoven fabric with theabove-mentioned woven or knitted material. The fibers capable ofconverting into ultra fine fibers are easily entangled with each otherby being subjected to the crimp processing. The crimp processing and cutprocessing may adopt known methods. As a method for entangling the fibercapable of converting into ultra fine fibers with the woven or knittedmaterial to obtain a sheet, known methods such as needle punching andwater-jet punching can be adopted.

The obtained sheet may be subjected to shrinkage treatment by hot wateror steam treatment for improving a sense of minuteness of the fiber.However, the shrinkage treatment at high temperature needs to becarefully performed for the reason that crimp is developed in thecomposite fiber composing the woven or knitted material, and whenelastomer is subjected in the state in the next step, a sheet is poor instretchability. The shrinkage treatment in this state is preferablyperformed at a temperature of 100° C. or less.

Next, step (ii) is described.

In step (ii), an ultra fine fiber with an average single fiber finenessof 0.001 dtex or more and 0.5 dtex or less is developed by treating witha solvent the sheet composed of the fiber capable of converting intoultra fine fibers and the woven or knitted material to thereafterprovide elastomer having polyurethane as a main component byimpregnating and solidifying solvent solution of elastomer havingpolyurethane as a main component into the sheet. Alternatively, with theorder reversed in these steps, elastomer having polyurethane as a maincomponent may be provided by impregnating and solidifying solventsolution of elastomer having polyurethane as a main component into thesheet composed of the fiber capable of converting into ultra fine fibersand the woven or knitted material to thereafter develop an ultra finefiber with an average single fiber fineness of 0.001 dtex or more and0.5 dtex or less by treating the sheet with a solvent.

Here, in the case where the fiber capable of converting into ultra finefibers is the sea-island type composite fiber, the components asdescribed above may be used as the sea component; in the case where thesea component is polyethylene, polypropylene or polystyrene, organicsolvents such as toluene and trichloroethylene can be used as thesolvent in step (ii). In the case where the sea component iscopolymerization polyester or polylactic acid, alkali aqueous solutionsuch as sodium hydroxide can be used as the solvent. In addition, in thecase where the sea component is water-soluble thermoplastic polyvinylalcohol resin, hot water can be used as the solvent. In any of thecases, the sheet including the sea-island type composite fiber can beimmersed and squeezed in solvent to thereby remove the sea component anddevelop an ultra fine fiber.

Examples of a method for providing elastomer having polyurethane as amain component to the sheet include a method for impregnating andwet-coagulating polyurethane solution containing elastomer as describedabove into the sheet, and a method for impregnating and dry-coagulatingthe polyurethane solution into the sheet; but not particularly limited.

In an embodiment of the present invention, as described above, elastomermay be provided to the sheet to thereafter develop an ultra fine fiber,but yet an ultra fine fiber is preferably developed to thereafterprovide elastomer. Elastomer grasps an ultra fine fiber by developing anultra fine fiber to thereafter provide elastomer, and so the sheetbecomes to be able to endure a longer-term use with no ultra fine fibersfalling off even in repetitive stretching. The degree of the grasp of anultra fine fiber by elastomer is preferably adjusted by the added amountof the water-soluble resin. In the case of providing elastomer tothereafter develop an ultra fine fiber, elastomer has a structure suchas not to grasp an ultra fine fiber, and so the added amount ofelastomer is preferably increased for making a sheet to be able toendure a long-term use. However, in this case, when shrinkage of wovenor knitted material is performed in step (iii), elastomer hinders wovenor knitted material so easily from shrinking that stretchability tendsto be developed with difficulty.

In the case of developing an ultra fine fiber to thereafter provideelastomer, water-soluble resin is preferably provided to the sheetobtained in step (i) before step (ii). By providing water-soluble resinto the sheet, the surface of the fiber capable of converting into ultrafine fibers and the surface of the composite fiber composing woven orknitted material are protected by the water-soluble resin. Specifically,the fiber bundle surface of the fiber capable of converting into ultrafine fibers and the surface of the composite fiber composing woven orknitted material are partially protected by the water-soluble resin, sothat in the case of providing elastomer having polyurethane as a maincomponent to the sheet in step (ii), the place where elastomer and thesingle fiber or the composite fiber are directly joined exists notcontinuously but partially on the surface of the single fiber located inthe outermost periphery of the fiber bundle of the ultra fine fibers andthe composite fiber composing woven or knitted material, whereby thebond area of elastomer to the ultra fine fibers and the composite fibermay be retained in a proper amount. As a result, the finally obtainedstretch sheet has a structure with a moderate degree of freedom to theultra fine fibers and the woven or knitted material while securing thephysical properties such as abrasion resistance, and can restrainshrinkage of woven or knitted material from being hindered in theshrinkage treatment in step (iii) while increasing the strength. Thus,in the shrinkage treatment in step (iii), the woven or knitted materialcan be further shrunk and the thread composed of the composite fiber inthe woven or knitted material has a hollow structure more easily, sothat the finally obtained sheet has favorable touch and sense of handfeeling and high stretchability.

Such water-soluble resin is not particularly limited, preferablypolyvinyl alcohol with a saponified degree of 80% or more.

The added amount of water-soluble resin is preferably 1% by weight ormore and 30% by weight or less with respect to the weight of the sheet.The added amount of 1% by weight or more allows the sheet to havefavorable touch and stretchability, while the added amount of 30% byweight or less allows the sheet to have favorable processability andphysical properties such as abrasion resistance.

Examples of a method for providing water-soluble resin include a methodfor impregnating and drying aqueous solution of water-soluble resin, butare not particularly limited. Drying temperature and drying time are notparticularly limited, and yet drying is preferably performed so that thetemperature of the sheet is less than 110° C. for the reason that thetemperature of the sheet is so high that the crimp of the woven orknitted material is developed. The temperature of heated air given fordrying may be 110° C. or more if the temperature of the sheet itself iskept at less than 110° C.

The provided water-soluble resin is favorably removed from the sheet byhot water before step (iii).

Next, step (iii) is described.

In step (iii), a sheet composed of woven or knitted material, ultra finefibers and elastomer having polyurethane as a main component is put in ajet dyeing machine, and woven or knitted material in the sheet arerubbed and shrunk under the condition of 110° C. or more.

In a method of an embodiment of the present invention, the shrinkage ofwoven or knitted material is achieved by subjecting it to treatment ofrubbing at a temperature of 110° C. or more with a jet dyeing machine.The rubbing by a jet dyeing machine is provided to the sheet under thecondition of 110° C. or more, so that the crimp of a thread and theshrinkage of woven or knitted material are developed, and the threadcomposed of the composite fiber in the sheet has a structure having acavity in the inside. As a result, stretchability is provided to thesheet, and favorable touch and grade can be further obtained.

A jet dyeing machine can be used for rubbing the sheet at a temperatureof 110° C. or more, and known jet dyeing machines can be used as the jetdyeing machine.

The treatment temperature needs to be 110° C. or more; the treatment athigher temperature allows the crimp of a thread and the shrinkage ofwoven or knitted material to be easily developed and allows the threadcomposed of the composite fiber to easily have a structure having acavity in the inside. However, the treatment at too high temperaturecauses thermal degradation in elastomer having polyurethane as a maincomponent; therefore, preferably 120° C. or more and 150° C. or less,more preferably 125° C. or more and 135° C. or less.

In an embodiment of the present invention, it is especially preferredthat the sheet be heated at high temperature in this step (iii) toshrink woven or knitted material and develop the crimp of a thread. Forexample, in the case where the woven or knitted material with shrinkageand crimp previously developed are inserted in step (ii), the fibers ofwoven or knitted material are cut by entanglement treatment such asneedle punching and exposed to the sheet surface, so that surfaceappearance grade is deteriorated and the thread composed of thecomposite fiber in the sheet does not have a structure having a cavityin the inside to occasionally cause a deterioration in stretchabilityand a deterioration in a sense of hand feeling and grade. In the case ofproviding a woven or knitted material having crimp developed withpolyurethane in step (ii), the shape of the sheet itself is fixed todevelop stretchability with difficulty. Thus, in an embodiment of thepresent invention, after being integrated into the sheet, it isdesirable that woven or knitted material in the sheet is shrunk so thatthe thread composed of the composite fiber have a structure having acavity in the inside.

Dyeing may be performed simultaneously with shrinkage treatment in step(iii). The dyestuff is not particularly limited but may be selected inaccordance with ultra fine fibers composing the sheet. For example,disperse dyestuff can be used in the case where the sheet is composed ofpolyester ultra fine fibers, and acidic dyestuff and premetalizeddyestuff can be used in the case where the sheet is composed ofpolyamide ultra fine fibers. In the case of dyeing with dispersedyestuff, reduction cleaning may be performed after dyeing.

A dyeing assistant is preferably used in dyeing for the purpose ofimproving uniformity and repeatability of dyeing. In addition, finishingcompound treatment such as softening agent (such as silicone), andantistatic agent may be performed, and finishing treatment may beperformed after dyeing or in the same bath as dyeing.

A sheet with stretchability in an embodiment of the present inventionmay be made into a nap-like sheet having the nap of ultra fine fibers onat least one side. For this purpose, raising treatment is preferablyperformed between step (ii) and step (iii) or after step (iii).

The raising treatment for forming nap on the sheet surface can beperformed by a method for buffing with the use of sandpaper and rollsander. A lubricant such as silicone emulsion may be provided before theraising treatment. An antistatic agent is preferably provided before theraising treatment for the reason that buffing powder caused from thesheet by buffing is to be accumulated on sandpaper with difficulty.

The sheet may be cut in half or divided into several pieces in the sheetthickness direction before step (ii) or step (iii).

A sheet obtained by a method of the present invention according to anexemplary embodiment as described above is so excellent in surfaceappearances, touch, stretch ratio and stretch-back ratio as to becapable of being appropriately used as interior material with verygraceful surface appearances for cover material of furniture and chairsand wall material, and cover material for seats and ceiling in vehiclecabins of automobiles, trains and aircrafts. In addition, the sheet maybe appropriately used as clothing material for shirts, jackets, bags,belts, wallet and a part thereof, and upper and trim of shoes such ascasual shoes, sport shoes, men's shoes and ladies' shoes.

EXAMPLES

Embodiments of the present invention are hereinafter described morespecifically by using examples, but not limited only to the followingexamples.

[Evaluation Methods]

(1) Intrinsic Viscosity

A sample polymer was dissolved by 0.8 g in 10 mL of ortho-chlorophenol(hereinafter abbreviated as OCP) to obtain relative viscosity ηr at atemperature of 25° C. from the following expression by using an Ostwaldviscometer and calculate intrinsic viscosity (IV).ηr=η/η ₀=(t×d)/(t ₀ ×d ₀)

Intrinsic viscosity IV=0.0242ηr+0.2634 wherein, η: viscometer of thepolymer solution

η₀: viscometer of OCP

t: fall time of the solution (second)

d: density of the solution (g/cm³)

t_(o): fall time of OCP (second)

d_(o): density of OCP (g/cm³)

(2) Average Single Fiber Fineness

The average single fiber fineness was calculated in such a manner that ascanning electron microscope (SEM) picture of the sheet cross sectionwas taken to randomly select circular or elliptic close to circle fibersby 100 pieces and measure the fiber diameters, which were converted intofineness by specific gravity of the raw material polymer of the fibers(1.38 g/cm³ in polyethylene terephthalate) to further calculate averagevalue of 100 pieces.

(3) Softening Point of Polyurethane

DMF solution of 25% by weight-polyurethane was left at room temperaturefor 20 hours and defoamed, and thereafter applied with a thickness of1.0 mm on a glass plate and dried by a circulating type drier at atemperature of 70° C. for 3 hours and by a vacuum dryer at a temperatureof 60° C. for 3 hours, and a polyurethane film is peeled off from theglass plate to obtain a dry film of polyurethane. With regard to theobtained polyurethane dry film, softening point was measured by usingthermal analysis equipment.

(4) Gelation Point of Polyurethane

The water dropping amount was regarded as gelation point when 100 g ofDMF solution of 1% by weight-polyurethane was stirred while droppingdistilled water into this solution and became slightly clouded after thecoagulation of polyurethane started on the temperature conditions of25±1° C.

(5) Confirmation of Cavity of a Thread in Woven or Knitted Material

A scanning electron microscope (SEM) picture of the sheet cross sectionwas taken to select a circular or elliptic close to circle line ofthread composing woven or knitted material and draw an approximatecircle as shown in FIG. 1. Subsequently, a line A connecting the outerperiphery of the thread and the center of the approximate circle wasdrawn to measure the length of a portion B where the line A and thefiber are superposed and to measure the ratio of the length of the lineB to the length of the line A. This was performed for 100 piecesrandomly selected, and the case where the average of 10 pieces was 80%or less was determined as a structure having a cavity inside the thread.

(6) Stretchability

Stretchability was evaluated by stretch ratio and stretch-back ratio.With regard to each direction of the sheet, the case where both stretchratio and stretch-back ratio exceeded target value was regarded as ‘P’in evaluation, namely, passed, and the case where either or both ofstretch ratio and stretch-back ratio did not exceed target value wasregarded as ‘F’ in evaluation, namely, failed. The case where either orboth of longitudinal direction and transversal direction passed wasdetermined as a sheet with stretchability, namely, ‘P’, and the casewhere both longitudinal direction and transversal direction failed wasdetermined as failed, namely, ‘F’.

Stretch Ratio

The stretch ratio of the sheet was measured in accordance with JIS L1096 (2005) 8.14.1 B method (constant load method). The length betweengrips was 50 cm.

A favorable level (target value) is 15% or more and 35% or less instretch ratio.

Stretch-Back Ratio

The stretch-back ratio of the sheet was measured in accordance with JISL 1096 (2005) 8.14.2 B-1 method (constant load method). The lengthbetween grips was 50 cm and the exposure time after removing the loadwas 1 hour.

A favorable level (target value) is 80% or more and 100% or less instretch-back ratio.

(7) Surface Appearance Grade

The surface grade of a leather-like sheet was evaluated in the followingmanner by visual observation and sensory evaluation with evaluators oftwenty persons in total of healthy ten male adults and female adultseach to regard the most evaluation as surface appearance grade. In thecase where the evaluation result was divided in the same number, worseevaluation was regarded as surface appearance grade. A favorable levelis ‘A’ or ‘B’.

A: dispersion state of the fibers is favorable with a sense ofminuteness and surface appearance is favorable

B: dispersion state of the fibers is partially somewhat unfavorable andsurface appearance is tolerably favorable

C: dispersion state of the fibers is entirely very poor and surfaceappearance is unfavorable

(8) Touch

The following evaluation was distinguished by the sense of touch withevaluators of twenty persons in total of healthy ten male adults andfemale adults each to regard the most evaluation as touch. In the casewhere the evaluation result was divided in the same number, worseevaluation was regarded as touch. A favorable level is ‘A’ or ‘B’.

A: very soft

B: soft

C: hard

D: very hard

(9) Pilling Evaluation

The pilling evaluation of the sheet was performed in such a manner thata load equivalent to 12 kPa was applied using Model 406 manufactured byJames H. Heal & Co. as Martindale abrasion tester and ABRASTIVE CLOTHSM25 manufactured by the same company as a standard rubbing cloth, andthe surface appearances of a sample after rubbing on the conditions ofan abrasion number of 20,000 was observed by visual observation. Thecriterion for evaluation was determined by surface appearances and thenumber of pills to evaluate in the following manner.

Fifth degree: surface appearances of the sample have no change from thestate before rubbing

Fourth and a half degree: nap of the sample surface lies and no pill iscaused

Fourth degree: one pill is caused on the sample surface

Third and a half degree: two or three pills are caused on the samplesurface

Third degree: four or five pills are caused on the sample surface

Second and a half degree: six or ten pills are caused on the samplesurface

Second degree: eleven or fifteen pills are caused on the sample surface

First and a half degree: sixteen or twenty pills are caused on thesample surface

First degree: twenty-one or more pills are caused on the sample surface

(10) Abrasion Loss

The same operation as the pilling evaluation was performed to calculateabrasion loss (mg) from the following expression:Abrasion loss (mg)=the weight before rubbing (mg)−the weight afterrubbing (mg);by using the weights before and after rubbing.(11) Polyurethane Molecular Weight of Sheet

The sheet was immersed in N,N-dimethylformamide in which lithiumchloride was dissolved at a concentration of 0.1 mol/l to extractpolyurethane and prepare solution so that the polyurethane concentrationwas 0.2% by weight. The weight-average molecular weight was calculatedfrom the obtained solution by using gel permeation chromatography(HLC-8020, manufactured by Tosoh Corp).

[Representation of Chemical Substances]

PU: polyurethane

PTMG: polytetramethylene glycol with a number-average molecular weightof 2000

PCL: polycaprolactone with a number-average molecular weight of 2000

PHC: polyhexamethylene carbonate with a number-average molecular weightof 2000

PNMOC: copolymerization polycarbonate diol derived from 1,9-nonanediolwith a number-average molecular weight of 2000, represented by thefollowing general formula (3), and 2-methyl-1,8-octanediol

(in the formula, n and m are positive integers and randomcopolymerization. R represents an aliphatic hydrocarbon group of either(CH₂)₉ or CH₂—CH(CH₃)—(CH₂)₆.)

PHMPC: copolymerization polycarbonate diol derived from 1,6-hexanediolwith a number-average molecular weight of 2000, represented by thefollowing general formula (4), and 3-methyl-1,5-pentanediol

(in the formula, x and y are positive integers and randomcopolymerization. R represents an aliphatic hydrocarbon group of either(CH₂)₆ or (CH₂)₂—CH(CH₃)—(CH₂)₂.)

MDI: 4,4′-diphenylmethane diisocyanate

EG: ethylene glycol

DMF: N,N-dimethylformamide

PET: polyethylene terephthalate

PVA: polyvinyl alcohol

[Polyurethane Kind]

(1) Polyurethane I (PU-I)

Polyisocyanate: MDI

Polyol: PTMG 70%, PCL 30%

Chain extender: EG

Softening point: 250° C.

Gelation point: 3.1 ml

(2) Polyurethane II (PU-II)

Polyisocyanate: MDI

Polyol: PHC 70%, PCL 30%

Chain extender: EG

Softening point: 210° C.

Gelation point: 7.1 ml

(3) Polyurethane III (PU-III)

Polyisocyanate: MDI

Polyol: PNMOC 60%, PHMPC 40%

Chain extender: EG

Softening point: 250° C.

Gelation point: 3.5 ml

(4) Polyurethane VI (PU-VI)

Polyisocyanate: MDI

Polyol: PHMPC 60%, PCL 20%, PTMG 20%

Chain extender: EG

Softening point: 250° C.

Gelation point: 4.9 ml

(Production of Fibers for Woven or Knitted Material)

Production Example 1

PET with an intrinsic viscosity (IV) of 0.78 and PET with an intrinsicviscosity (IV) of 0.51 were melted separately, discharged from a12-outlet composite spinneret at a spinning temperature of 295° C. and acomposite ratio (% by weight) of 50:50, and taken up at a spinning speedof 1450 m/minute to obtain side-by-side type composite structure undrawnyarn with 12 filaments.

The yarn was drawn at a draw ratio of 2.6 times by using a heatedroll-heating plate drawing machine to obtain drawn yarn with 56 dtex and12 filaments.

Production Example 2

PET with an intrinsic viscosity (IV) of 0.65 was discharged from a72-outlet spinneret at a spinning temperature of 295° C., and taken upat a spinning speed of 1650 m/minute to obtain undrawn yarn with 72filaments.

The yarn was drawn at a draw ratio of 2.8 times by using a heatedroll-heating plate drawing machine to obtain drawn yarn with 84 dtex and72 filaments.

(Production of Woven Goods)

Production Example 3

Plain woven material were produced by using as warp yarn twisted yarnsuch that the drawn yarn obtained in Production Example 1 was twisted by1500 times/m (a twisting factor of 11200) as warp yarn and using as weftyarn twisted yarn such that the drawn yarn obtained in ProductionExample 2 was twisted by 2500 times/m (a twisting factor of 22900) asweft yarn.

Production Example 4

Plain woven material were produced by using for both warp yarn and weftyarn twisted yarns such that the drawn yarns obtained in ProductionExample 1 were made into two folded yarn and twisted by 1800 times/m (atwisting factor of 18900).

Production Example 5

Plain woven material were produced by using for both warp yarn and weftyarn twisted yarns such that the drawn yarns obtained in ProductionExample 2 were twisted by 2500 times/m (a twisting factor of 22900).

Production Example 6

Plain woven material were produced by using as warp yarn twisted yarnsuch that the drawn yarn obtained in Production Example 1 was twisted by1500 times/m (a twisting factor of 11200) and using as weft yarn twistedyarn such that the drawn yarn obtained in Production Example 2 wastwisted by 2500 times/m (a twisting factor of 22900).

The obtained woven material were processed at a temperature of 130° C.for 30 minutes by a jet dyeing machine and thereafter dried at atemperature of 130° C. by using a pin tenter to produce woven materialwith crimp of warp yarn developed.

(Production of Sheet)

Example 1

PET as an island component and polystyrene as a sea component weremelted and spun by using a sea-island type composite spinneret with anisland number of 36 at a island/sea weight ratio of 55/45, thereafterdrawn and crimped, and thereafter cut into 51 mm to obtain raw cotton ofa sea-island type composite fiber with a single fiber fineness of 3.1dtex.

A laminated web was formed through the steps of card and cloth wrapperby using this raw cotton of a sea-island type composite fiber, andneedle-punched at a punching number of 600 pieces/cm², and thereafterthe woven material produced in Production Example 3 were inserted aboveand below the web, needle-punched at a punching number of 2900pieces/cm² to stick the web and the woven material together and then toobtain a sheet. This sheet was shrunk by hot water at a temperature of96° C. and thereafter impregnated into 5%-PVA aqueous solution, anddried by heated air at a temperature of 110° C. for 10 minutes to obtaina sheet such that the PVA weight with respect to the weight of the sheetwas 4% by weight. The sea component of this sheet was removed bydissolving in trichloroethylene to obtain a sea component-removed sheetwith ultra fine fibers and the woven material entangled. The averagesingle fiber fineness was 0.05 dtex by scanning electron microscope(SEM) observation of the sea component-removed sheet cross section.

This sea component-removed sheet composed of the ultra fine fibers andthe woven material was impregnated into DMF solution of polyurethane Iprepared for a solid concentration of 12% to coagulate polyurethane inaqueous solution with a DMF concentration of 30%. Thereafter, PVA andDMF were removed by hot water and dried by heated air at a temperatureof 110° C. for 10 minutes to obtain a sheet such that the polyurethaneweight with respect to the island component weight (the total weight ofthe ultra fine fibers and the woven material) of the sheet was 20% byweight.

Then, the obtained sheet was cut in half in the thickness direction, andthe cut-in-half surface was buffed by endless sandpaper with a sandpapercount of No. 240 to form a napped surface.

The sheet thus obtained was simultaneously shrunk and dyed by a jetdyeing machine under the condition of 130° C., and thereafter dried by adrier to obtain a sheet.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 26% and astretch-back ratio of 95% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 143000.

Example 2

PET as an island component and polystyrene as a sea component weremelted and spun by using a sea-island type composite spinneret with anisland number of 16 at a island/sea weight ratio of 80/20, thereafterdrawn and crimped, and thereafter cut into 51 mm to obtain raw cotton ofa sea-island type composite fiber with a single fiber fineness of 3.8dtex.

A laminated web was formed through the steps of card and cloth wrapperby using this raw cotton of a sea-island type composite fiber, andneedle-punched at a punching number of 300 pieces/cm², and thereafterthe woven material produced in Production Example 4 were inserted aboveand below the web, needle-punched at a punching number of 3400pieces/cm² to stick the web and the woven material together and then toobtain a sheet. This sheet was shrunk by hot water at a temperature of96° C. and thereafter impregnated into 5%-PVA aqueous solution, anddried by heated air at a temperature of 110° C. for 10 minutes to obtaina sheet such that the PVA weight with respect to the weight of the sheetwas 7% by weight. The sea component of this sheet was removed bydissolving in trichloroethylene to obtain a sea component-removed sheetwith ultra fine fibers and the woven material entangled. The averagesingle fiber fineness was 0.19 dtex by scanning electron microscope(SEM) observation of the sea component-removed sheet cross section.

This sea component-removed sheet composed of the ultra fine fibers andthe woven material was impregnated into DMF solution of polyurethane IIprepared for a solid concentration of 12% to coagulate polyurethane inaqueous solution with a DMF concentration of 30%. Thereafter, PVA andDMF were removed by hot water and dried by heated air at a temperatureof 110° C. for 10 minutes to obtain a sheet such that the polyurethaneweight with respect to the island component weight (the total weight ofthe ultra fine fibers and the woven material) of the sheet was 31% byweight.

Then, the obtained sheet was cut in half in the thickness direction, andthe cut-in-half surface was buffed by endless sandpaper with a sandpapercount of No. 240 to form a napped surface.

The sheet thus obtained was simultaneously shrunk and dyed by a jetdyeing machine under the condition of 130° C., and thereafter dried by adrier to obtain a sheet.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inboth warp yarn and weft yarn. The obtained sheet had a stretch ratio of18% and a stretch-back ratio of 92% in the transversal direction, and astretch ratio of 18% and a stretch-back ratio of 86% in the longitudinaldirection, and favorable stretchability in both the transversaldirection and the longitudinal direction. The sheet exhibited favorableresults also in surface appearance grade, touch, pilling evaluation andabrasion loss. In addition, the molecular weight of polyurethane in thesheet was 201000.

Example 3

PET as an island component and polystyrene as a sea component weremelted and spun by using a sea-island type composite spinneret with anisland number of 100 at a island/sea weight ratio of 50/50, thereafterdrawn and crimped, and thereafter cut into 51 mm to obtain raw cotton ofa sea-island type composite fiber with a single fiber fineness of 4.2dtex.

A laminated web was formed through the steps of card and cloth wrapperby using this raw cotton of a sea-island type composite fiber, andneedle-punched at a punching number of 600 pieces/cm², and thereafterthe woven material produced in Production Example 3 were inserted aboveand below the web, needle-punched at a punching number of 2900pieces/cm² to stick the web and the woven material together and then toobtain a sheet. This sheet was shrunk by hot water at a temperature of96° C. and thereafter impregnated into 10%-PVA aqueous solution, anddried by heated air at a temperature of 110° C. for 10 minutes to obtaina sheet such that the PVA weight with respect to the weight of the sheetwas 21% by weight. The sea component of this sheet was removed bydissolving in trichloroethylene to obtain a sea component-removed sheetwith ultra fine fibers and the woven material entangled. The averagesingle fiber fineness was 0.02 dtex by scanning electron microscope(SEM) observation of the sea component-removed sheet cross section.

This sea component-removed sheet composed of the ultra fine fibers andthe woven material was impregnated into DMF solution of polyurethane IIIprepared for a solid concentration of 12% to coagulate polyurethane inaqueous solution with a DMF concentration of 30%. Thereafter, PVA andDMF were removed by hot water and dried by heated air at a temperatureof 110° C. for 10 minutes to obtain a sheet such that the polyurethaneweight with respect to the island component weight (the total weight ofthe ultra fine fibers and the woven material) of the sheet was 25% byweight.

Then, the obtained sheet was cut in half in the thickness direction, andthe cut-in-half surface was buffed by endless sandpaper with a sandpapercount of No. 240 to form a napped surface.

The sheet thus obtained was simultaneously shrunk and dyed by a jetdyeing machine under the condition of 130° C., and thereafter dried by adrier to obtain a sheet.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 32% and astretch-back ratio of 88% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 258000.

Example 4

PET as an island component and polystyrene as a sea component weremelted and spun by using a sea-island type composite spinneret with anisland number of 36 at a island/sea weight ratio of 55/45, thereafterdrawn and crimped, and thereafter cut into 51 mm to obtain raw cotton ofa sea-island type composite fiber with a single fiber fineness of 3.1dtex.

A laminated web was formed through the steps of card and cloth wrapperby using this raw cotton of a sea-island type composite fiber, andneedle-punched at a punching number of 600 pieces/cm², and thereafterthe woven material produced in Production Example 3 were inserted aboveand below the web, needle-punched at a punching number of 2900pieces/cm² to stick the web and the woven material together and then toobtain a sheet. This sheet was shrunk by hot water at a temperature of96° C. and thereafter impregnated into 5%-PVA aqueous solution, anddried by heated air at a temperature of 110° C. for 10 minutes to obtaina sheet such that the PVA weight with respect to the weight of the sheetwas 5% by weight. Thereafter, the sheet was impregnated into DMFsolution of polyurethane I prepared for a solid concentration of 12% tocoagulate polyurethane in aqueous solution with a DMF concentration of30%. Then, DMF was removed by hot water and dried by heated air at atemperature of 110° C. for 10 minutes to obtain a sheet such that thepolyurethane weight with respect to the island component weight (thetotal weight of the ultra fine fibers and the woven material) of thesheet was 22% by weight. The sea component of this sheet was removed bydissolving in trichloroethylene to obtain a sheet composed of the ultrafine fibers, the woven material and polyurethane. The average singlefiber fineness was 0.05 dtex by scanning electron microscope (SEM)observation of the sheet cross section.

Then, the obtained sheet was cut in half in the thickness direction, andthe cut-in-half surface was buffed by endless sandpaper with a sandpapercount of No. 240 to form a napped surface.

The sheet thus obtained was simultaneously shrunk and dyed by a jetdyeing machine under the condition of 130° C., and thereafter dried by adrier to obtain a sheet.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 29% and astretch-back ratio of 86% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 147000.

Example 5

A sheet was obtained by performing the same process as Example 1 exceptfor changing the added amount of PVA and the added amount of PU to 5%and 5%, respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had poor abrasion resistance but yetstretchability in the transversal direction, and favorable surfaceappearance grade and touch. In addition, the molecular weight ofpolyurethane in the sheet was 134000.

Example 6

A sheet was obtained by performing the same process as Example 1 exceptfor cutting a sea-island type composite fiber into 15 mm, and changingthe added amount of PVA and the added amount of PU to 5% and 23%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had many abrasion losses but yetstretchability in the transversal direction, and favorable surfaceappearance grade, touch and pilling evaluation. In addition, themolecular weight of polyurethane in the sheet was 139000.

Example 7

A sheet was obtained by performing the same process as Example 1 exceptfor providing no PVA and changing the added amount of PU to 14%.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 16% and astretch-back ratio of 97% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 131000.

Example 8

A sheet was obtained by performing the same process as Example 1 exceptfor changing the added amount of PVA and the added amount of PU to 22%and 38%, respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 19% and astretch-back ratio of 87% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 149000.

Example 9

A sheet was obtained by performing the same process as Example 1 exceptfor cutting a sea-island type composite fiber into 89 mm, and changingthe added amount of PVA and the added amount of PU to 21% and 18%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 30% and astretch-back ratio of 88% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 141000.

Example 10

A sheet was obtained by performing the same process as Example 1 exceptfor changing the added amount of PVA and the added amount of PU to 30%and 25%, respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 34% and astretch-back ratio of 87% in the transversal direction, and favorablestretchability in the transversal direction. In addition, the sheetexhibited somewhat many abrasion losses but yet favorable results insurface appearance grade, touch and pilling evaluation. The molecularweight of polyurethane in the sheet was 139000.

Example 11

A sheet was obtained by performing the same process as Example 1 exceptfor replacing polyurethane I with polyurethane IV, and changing theadded amount of PVA and the added amount of PU to 20% and 19%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 28% and astretch-back ratio of 90% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 198000.

Example 12

A sheet was obtained by performing the same process as Example 1 exceptfor changing the added amount of PVA and the added amount of PU to 21%and 44%, respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 16% and astretch-back ratio of 95% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 151000.

Example 13

A sheet was obtained by performing the same process as Example 1 exceptfor cutting a sea-island type composite fiber into 25 mm, and changingthe added amount of PVA and the added amount of PU to 5% and 21%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 25% and astretch-back ratio of 95% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 142000.

Example 14

A sheet was obtained by performing the same process as Example 1 exceptfor cutting a sea-island type composite fiber into 102 mm, and modifyingthe added amount of PVA and the added amount of PU to 5% and 21%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 26% and astretch-back ratio of 94% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 135000.

Example 15

A sheet was obtained by performing the same process as Example 1 exceptfor replacing polyurethane I with polyurethane II, and changing theadded amount of PVA and the added amount of PU to 21% and 25%,respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, it was confirmed that a cavity existed inweft yarn. The obtained sheet had a stretch ratio of 19% and astretch-back ratio of 96% in the transversal direction, and favorablestretchability in the transversal direction. The sheet exhibitedfavorable results also in surface appearance grade, touch, pillingevaluation and abrasion loss. In addition, the molecular weight ofpolyurethane in the sheet was 205000.

Comparative Example 1

A sheet was obtained by performing the same process as Example 1 exceptfor using the woven material produced in Production Example 5, andchanging the added amount of PVA and the added amount of PU into 3% and19%, respectively.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, a cavity existed in neither warp yarn norweft yarn. The obtained sheet exhibited favorable surface appearancegrade, touch, pilling evaluation and abrasion loss, but yet had nostretchability. The molecular weight of polyurethane in the sheet was141000.

Comparative Example 2

A sheet with a napped surface formed was obtained by performing the sameprocess as Example 1 except for using the woven material with crimpdeveloped, which was produced in Production Example 6, and changing theadded amount of PVA and the added amount of PU to 6% and 22%,respectively. The sheet thus obtained was dyed by a jet dyeing machineunder the condition of 130° C., and thereafter dried by a drier toobtain a sheet.

With regard to this sheet, as a result of observing a cavity of thethread in the woven material, a cavity existed in neither warp yarn norweft yarn. The obtained sheet exhibited favorable touch and abrasionloss, but yet somewhat poor pilling evaluation, and had nostretchability. The fibers of the woven material were exposed to theproduct surface, so that the grade was very poor. The molecular weightof polyurethane in the sheet was 142000.

The conditions and results of Examples and Comparative Examples areshown together in Tables 1 to 3.

TABLE 1 Woven material weft yarn Woven material warp yarn Number ofNumber of twist Crimping twist Crimping Crimp Thread kind (times/m)factor Thread kind (times/m) factor development Production Production1500 11200 Production 2500 22900 Absent Example 3 Example 1 Example 2Production Production 1800 18900 Production 1800 18900 Absent Example 4Example 1 into Example 1 into two folded yarn two folded yarn ProductionProduction 2500 22900 Production 2500 22900 Absent Example 5 Example 2Example 2 Production Production 1500 11200 Production 2500 22900 PresentExample 6 Example 1 Example 2

TABLE 2 Ultra fine fibers PVA added PU added Timing of sea FinenessFiber length amount amount component (dtex) (mm) Kind of Woven material(wt. %) PU kind (wt. %) dissolution Example 1 0.05 51 Production Example3 4 PU-I 20 Before (woven material having composite impregnating fiberas weft yarn ) Example 2 0.19 51 Production Example 4 7 PU-II 31 Before(woven material having composite impregnating fiber as weft yarn andwarp yarn ) Example 3 0.02 51 Production Example 3 21 PU-III 25 Before(woven material having composite impregnating fiber as weft yarn )Example 4 0.05 51 Production Example 3 5 PU-I 22 after (woven materialhaving composite impregnating fiber as weft yarn ) Example 5 0.05 51Production Example 3 5 PU-I 5 Before (woven material having compositeimpregnating fiber as weft yarn ) Example 6 0.05 15 Production Example 35 PU-I 23 Before (woven material having composite impregnating fiber asweft yarn ) Example 7 0.05 51 Production Example 3 0 PU-I 14 Before(woven material having composite impregnating fiber as weft yarn )Example 8 0.05 51 Production Example 3 22 PU-I 38 Before (woven materialhaving composite impregnating fiber as weft yarn ) Example 9 0.05 89Production Example 3 21 PU-I 18 Before (woven material having compositeimpregnating fiber as weft yarn ) Example 10 0.05 51 Production Example3 30 PU-I 25 Before (woven material having composite impregnating fiberas weft yarn ) Example 11 0.05 51 Production Example 3 20 PU-IV 19Before (woven material having composite impregnating fiber as weft yarn) Example 12 0.05 51 Production Example 3 21 PU-I 44 Before (wovenmaterial having composite impregnating fiber as weft yarn ) Example 130.05 25 Production Example 3 5 PU-I 21 Before (woven material havingcomposite impregnating fiber as weft yarn ) Example 14 0.05 102Production Example 3 5 PU-I 21 Before (woven material having compositeimpregnating fiber as weft yarn ) Example 15 0.05 51 Production Example3 21 PU-II 25 Before (woven material having composite impregnating fiberas weft yarn ) Comparative 0.05 51 Production Example 5 3 PU-I 19 BeforeExample 1 (ordinary woven material) impregnating Comparative 0.05 51Production Example 6 6 PU-I 22 Before Example 2 (woven materila havingcomposite impregnating fiber as weft yarn (after

TABLE 3 Stretchability PU Cavity of Stretch ratio Stretch-back ratioEvaluation Surface Pilling Abrasion molecular composite Trans- Longi-Trans- Longi- Trans- Longi- Gen- appearance evaluation loss weight infibers versal tudinal versal tudinal versal tudinal eral grade Touch(degree) (mg) the sheet Example 1 Present 26 5 95 92 P F P A B 4.5 2.1143000 Example 2 Present 18 18 92 86 P P P A B 4.5 4.5 201000 Example 3Present 32 11 88 91 P F P A A 4.5 7.9 258000 Example 4 Present 29 11 8688 P F P B B 3.5 9.8 147000 Example 5 Present 27 10 95 92 P F P B A 112.1 134000 Example 6 Present 26 7 85 92 P F P A B 4.5 16.2 139000Example 7 Present 16 3 97 96 P F P A B 4.5 1.9 131000 Example 8 Present19 6 87 93 P F P A A 4.5 5.1 149000 Example 9 Present 30 10 88 90 P F PB A 4.5 1.7 141000 Example 10 Present 34 13 87 91 P F P A A 3.5 11.3139000 Example 11 Present 28 9 90 90 P F P A A 4.5 8.1 198000 Example 12Present 16 5 95 95 P F P A B 4.5 3.9 151000 Example 13 Present 25 5 9593 P F P A B 4.5 9.7 142000 Example 14 Present 26 4 94 92 P F P B B 4.51.8 135000 Example 15 Present 19 6 96 94 P F P A B 4.5 5.1 205000Comparative Absent 11 4 82 93 F F F B B 4.5 1.9 141000 Example 1Comparative Absent 21 9 73 95 F F F C B 3.5 5.5 142000 Example 2

The invention claimed is:
 1. A stretch sheet including woven or knittedmaterial including thread composed of a composite fiber such that twokinds or more of polyethylene terephthalate polymers different inintrinsic viscosity are stuck together in a side-by-side type along thefiber length direction and/or of a core-in-sheath type composite fibersuch that two kinds or more of polyethylene terephthalate polymersdifferent in intrinsic viscosity form an eccentric core-in-sheathstructure, an ultra fine fiber with an average single fiber fineness of0.001 dtex or more and 0.5 dtex or less, and an elastomer havingpolyurethane as a main component, in which the thread composing woven orknitted material has a structure having a cavity in its inside, whereinthe cavity is formed by heating under a condition of 110° C. or more,wherein the elastomer is partially joined to the thread having a cavitywhen being joined to the thread and a gelation point of the polyurethaneis 2.5 ml or more and 6 ml or less, and a softening point of thepolyurethane is greater than 240° and 300° C. or less; wherein a nappedsurface is formed; and wherein the content of the polyurethane is 10% byweight or more and 40% by weight or less with respect to the totalweight of the ultra fine fiber and the woven or knitted material.
 2. Thestretch sheet according to claim 1, wherein the softening point of thepolyurethane is greater than 250° C. and 300° C. or less.
 3. The stretchsheet according to claim 1, in which stretch ratio in a longitudinaldirection and/or a transversal direction is 15% or more and 35% or less,and a stretch-back ratio in the longitudinal direction and/or thetransversal direction is 80% or more and 100% or less.
 4. The stretchsheet according to claim 1, in which the polyurethane is polycarbonatepolyurethane having a polycarbonate skeleton represented by thefollowing general formulae (1) and (2):

wherein, R₁ and R₂ are aliphatic hydrocarbon groups with a carbon numberof 7 to 11, and may be same or different; n and m are positive integers;and R₁ and R₂ are block copolymerization or random copolymerization inthe case of being different;

wherein, R₃ and R₄ are aliphatic hydrocarbon groups with a carbon numberof 3 to 6, and may be same or different; x and y are positive integersand R₃ and R₄ are block copolymerization or random copolymerization inthe case of being different.
 5. The stretch sheet according to claim 1,in which the fiber length of the ultra fine fiber is 25 mm or more and90 mm or less.
 6. A method for producing the stretch sheet according toclaim 1, including the following steps (i) to (iii) in this order: (i)producing a sheet by entangling woven or knitted material including thethread composed of the two kinds or more of polyethylene terephthalatepolymers, with a fiber capable of converting into ultra fine fiberscomposed of two kinds or more of polymeric substances different insolubility in solvent; (ii) developing the ultra fine fiber by treatingthe sheet with a solvent to thereafter provide the elastomer havingpolyurethane as a main component by impregnating and solidifying asolvent solution of elastomer having polyurethane as a main componentinto the sheet, or of providing an elastomer having polyurethane as amain component by impregnating and solidifying a solvent solution ofelastomer having polyurethane as a main component into the sheet tothereafter develop the ultra fine fiber with an average single fiberfineness of 0.001 dtex or more and 0.5 dtex or less by treating thesheet with a solvent; and (iii) rubbing and shrinking the woven orknitted material under the condition of 110° C. or more.
 7. The methodfor producing a stretch sheet according to claim 6, in which elastomerhaving polyurethane as a main component is provided after developing anultra fine fiber in step (ii).
 8. The method for producing a stretchsheet according to claim 7, in which a water-soluble resin is providedto the sheet before step (ii).